The Occluded Artery Trial (OAT) is an NHLBI-funded international, multicenter, randomized trial testing the hypothesis that percutaneous coronary intervention with optimal medical therapy is superior in reducing clinical events compared to optimal medical therapy alone in stable, but high-risk, post-myocardial infarction patients. OAT patients have totally occluded infarct-related arteries 3-28 days after myocardial infarction (Ml) and at least one additional high risk feature, either reduced left ventricular function (ejection fraction <50%) or proximal coronary artery occlusion. Patients were randomized between 2000 and 2005 to either medical management or medical management plus percutaneous coronary intervention and stenting. The primary endpoint was a composite of death, class IV congestive heart failure (CHF) and recurrent Ml. After an average of three years of follow up of 2,166 enrolled patients, there was no significant difference between the treatment groups for the primary endpoint. This application for a competitive renewal proposes: A) to extend follow up by an additional 3 years to achieve an average follow up of approximately 6 years on the OAT cohort to examine late trends in events and quality of life and;B) to perform additional in-depth analyses on the original OAT cohort followed for 3 years. Extended follow up will also increase power to examine pre-specified subgroups. Extension of follow up in OAT is designed to provide the medical community with definitive data on the risks and benefits of a strategy of routine PCI of persistently occluded infarct-related arteries in stable patients late post-MI. OAT has over 200 participating clinical sites, a Clinical Coordinating Center at New York University Medical School, a Co-CCC at Mount Sinai Medical Center, a Data Coordinating Center at Maryland Medical Research Institute and a quality of Life Coordinating Center at Duke Clinical Research Institute. (End of Abstract)